The present invention pertains to an improved brake and release for a strapping tool. More particularly, the present invention is directed to a one-way clutch brake and release for a powered strapping tool.
Strapping tools are well-known in the art. These tools come in a wide variety of types, from fully manual tools to automatic, table-top tools. These tools are generally specifically designed for use with metal strapping or plastic/polymeric type strapping.
A strapper for applying plastic or polymeric strapping materials is powered to provide energy for tensioning the strap and adhering the strapping material onto itself. A typical strapper tool includes a body, one or more motors, a foot (which rests on the load), a tensioning wheel, a vibrating or sealing element and, typically, a pneumatic module to route air and provide control of the tool.
In use of the tool, first and second courses of strap material are passed over the foot of the tool, between the foot and the tensioning wheel. The strap is tensioned by rotation of the wheel. As the strap is tensioned, is also tightens onto the tool foot, holding the foot to the load. The strap is sealed to itself (as by welding) and the free end of the strap is cut. Although this does in fact strap the load, it also retains the tool (at the foot) sealed to the load.
To permit removing the tool from the load, the many tools are configured to allow the tensioning wheel to rollback, a small amount. This retains the strap in tension, but releases tension just enough to allow the tool foot to be pulled from between the strap and the load.
Various arrangements are known for permitting a light amount of rollback. For example, pneumatic systems are known that use a delay in the pneumatic circuit that permits a slight rollback following tensioning. Other strapping tools use a complex gearing arrangement to permit rollback.
Accordingly, there is a need for a simplified motor brake and release arrangement that provides rollback in a strapping tool. Desirably, such an arrangement eliminates the need for pneumatics in providing rollback. Most desirably, such a brake and release arrangement provides a positive brake from excessive rollback.